1. Field of the Invention
The present invention relates to semiconductor integrated circuits, and more particularly, to a semiconductor integrated circuit that can prevent the temperature of the surface of a semiconductor chip from rising excessively.
2. Description of the Background Art
The consumption current of semiconductor integrated circuits such as video signal processing semiconductor integrated circuits used in high definition television (HDTV) equipments is increasing these recent years due to the large scale integration and higher operation speed. The operating temperature of the semiconductor integrated circuit usually rises during its use due to such large consumption current. As a result, the temperature of the semiconductor chip surface sometimes becomes higher than the permissible limit temperature (approximately 150.degree. C.). If the semiconductor chip is left in a state where the surface temperature thereof in higher than the limit temperature, defect may occur in the circuit device. This may also cause accident such as fire and the like. approaches such as providing a radiating plate in the semiconductor integrated circuit have been taken to reduce the rise of temperature in such semiconductor chips.
A semiconductor integrated circuit comprising a PN junction diode as a temperature sensor is disclosed in Japanese Patent Laying-Open Nos. 59-163528 and 59-166826, for example. However, there were no positive approaches taken to reduce the surface temperature of the semiconductor chips or to warn the user of the rise in temperature using the detected output of the temperature sensor.
Conventional semiconductor integrated circuits does not have means to detect the surface temperature of the semiconductor chip for notifying the detected temperature to the user or for automatically reducing the temperature of the surface itself. There is the possibility of defect in the circuit device or occurrence of accidents such as fire due to the rise in temperature of the chip surface when the semiconductor integrated circuit is operated continuously.